![]() Artist's concept of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite. | |
Names | NASA-ISRO Synthetic Aperture Radar NISAR |
---|---|
Mission type | Radar imaging |
Operator | NASA / ISRO |
COSPAR ID | 2025-163A |
SATCAT no. | 65053 ![]() |
Website | nisar www |
Mission duration | Planned: 5 years [1] [2] Duration: 17 days |
Spacecraft properties | |
Spacecraft | NISAR |
Bus | I-3K [3] |
Manufacturer | NASA & ISRO |
Launch mass | 2,393 kg (5,276 lb) [4] |
Power | 6,500 watts |
Start of mission | |
Launch date | July 30 2025, 12:10 UTC 05:40pm IST [5] |
Rocket | GSLV F16 (4 meter fairing) [3] |
Launch site | Satish Dhawan Space Centre |
Contractor | ISRO |
Orbital parameters | |
Reference system | Geocentric orbit [1] |
Regime | Sun-synchronous orbit [6] |
Altitude | 747 km (464 mi) |
Perigee altitude | 747 km (464 mi) |
Apogee altitude | 747 km (464 mi) |
Inclination | 98.5° |
Transponders | |
Band | S-band L-band |
Instruments | |
L-band (24-cm wavelength) Polarimetric Synthetic Aperture Radar S-band (12-cm wavelength) Polarimetric Synthetic Aperture Radar | |
![]() NISAR mission logo |
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual-frequency Synthetic Aperture Radar (SAR) on an Earth observation satellite (EOS) in 2025. It will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing, to observe and understand natural processes on Earth. For example, its left-facing instruments will study the Antarctic cryosphere. [7] With a total cost estimated at US$1.5 billion, NISAR is likely to be the world's most expensive Earth-imaging satellite. [8]
The NASA-ISRO Synthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth's land and ice masses four to six times a month at resolutions of 5 to 10 meters. [9] It is designed to observe and measure some of the planet's most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides. [10] [11]
The mission is a partnership between NASA and ISRO. [10] Under the terms of the agreement, NASA will provide the mission's L-band synthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific data GPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide the satellite bus, an S-band synthetic aperture radar (SAR), the launch vehicle, and associated launch services. [12]
All data from NISAR will be freely available one to two days after observation and within hours in case of emergencies like natural disasters. [9] Data collected from NISAR will reveal information about the evolution and state of Earth's crust, help scientists better understand our planet's natural processes and changing climate, and aid future resource and hazard management. [10]
The satellite will be three-axis stabilized. It will use a 12 m (39 ft) deployable mesh antenna and will operate on both the L- and S- microwave bands. [10] The aperture mesh reflector (antenna) will be supplied by Astro Aerospace. [13] Weighing about 142 pounds (64 kilograms), the reflector features a cylindrical frame made of 123 composite struts and a gold-plated wire mesh and is the largest of its kind deployed in space. [14]
The National Centre of Geodesy facilities at IIT-Kanpur and IIT-Patna will host a corner reflector for NISAR.It will play a key role in calibration and course correction of the Nisar satellite's radar during the in-orbit checkout phase. [15]
ISRO's share of the project cost is about ₹788 crore (US$93 million), and NASA's share is about US$1,118 million ($1.118 billion). [16] [17] [15]
The satellite was fully integrated in January 2024 and was performing its final testing and analysis in preparation for launch. [18] However, in an interview with the Times of India , Chairman of ISRO Sreedhara Panicker Somanath said that though the GSLV for NISAR will be built by March-April 2024, the satellite is still undergoing tests and they were expecting some delay. [19] Tests found that the large primary radar reflector might face higher-than-expected temperatures when stowed during flight and so it was returned to JPL, its manufacturer in California, to apply a reflective coating to mitigate the risk of overheating. [20] [21] It was the first GSLV Mk II launch to Low Earth orbitand to SSPO
On 15 October 2024, after the completion of all checks and tests, NASA's C-130 took off from Wallops Flight Facility in Virginia to embark on the multi-leg, multi-day journey to India. The flight first stopped at March Air Reserve Base to retrieve the spacecraft followed by strategic stops at Hickam Air Force Base, Hawaii; Andersen Air Force Base, Guam; Clark Air Base, Philippines and reached HAL Airport in Bengaluru, India. [22] [23] By late January 2025, the satellite had finished all preliminary checkout in Bengaluru and was ready to be shipped to SDSC. [24] By May 14 technicians had placed the satellite in a specialized container and transported it about 360 kilometers by truck to Satish Dhawan Space centre, where it arrived following day. [25]
NISAR lifted off aboard an ISRO Geosynchronous Satellite Launch Vehicle rocket at 5:40 p.m. IST on the 30th of July 2025. ISRO ground controllers in Bengaluru began communicating with NISAR about 18 minutes after launch, at just after 8:29 a.m. EDT, and confirmed it is operating as expected. It was the GSLV rocket’s first mission to Sun-synchronous polar orbit. [26] [27] [28] The satellite will enter a 90-day Checkout phase and deploy its primary Radar reflector before beginning of its operational life. [29] The orbit will be a Sun-Synchronous Orbit (SSO), dawn-to-dusk type. The planned mission life is 5 years. [1]
The deployment process for the spacecraft stared on August 9 2025 with the deployment of the 9 meter long booms first joint. The book was fully deployed by August 13th. 17 days after launch, on August 15th, ISRO and NASA mission controllers fired small explosive bolts to unfurl the 12 meters wide drum-shaped primary radar reflector for NISAR.The whole bloom process took 37 minutes and was completed with the locking of cables and activation of motors to fix the reflectors final shape. The spacecraft is expected to begin science operations by Fall 2025. [30] [31]